Field of the Invention
The present invention relates to a polishing pad and a chemical mechanical polishing (CMP) apparatus for polishing a workpiece, such as a metal body, to a mirror finish. The present invention further relates to a method of polishing the workpiece using such a chemical mechanical polishing apparatus.
Description of the Related Art
From a viewpoint of design, there has been a demand for mirror-polishing a workpiece having a three-dimensional surface constituted by a combination of a planar surface and a curved surface. Examples of such a workpiece include a metal body made of aluminum, stainless steel, or the like, and a resin body. The body may be used in, for example, a cellular phone, a smart phone, a multifunction mobile terminal, a portable game device, a camera, a watch, a music media player, a personal computer, car parts, ornaments, medical equipment, or the like.
A conventional lapping technique and a conventional polishing technique can polish the planar surface to a mirror finish. However, it is very difficult for these techniques to polish the curved surface to a mirror finish. A hand-type buffing process can polish the curved surface and the planar surface, but cannot achieve a mirror-finished surface (particularly a mirror-finished planar surface) to the same level as the lapping technique and the polishing technique.